Air-pump.



C. S. STEVENS.

AIR PUMP.

APPLICATION FILED JAN. 17, 1913. Patented Jan 25, 1916' 2 SHEETS-SHEET 1.

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THE COLUMBIA PLANOGRAPH c0., WASHINGTON, o

C. S. STEVENS.

AIR PUMP.

APPLICATION FILED mm], 1913.

1,169,438. Patented Jan. 25, 1916.

2 SHEETSSHEET 2.

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%TATE% PATENT @FFTQE.

CLAYTON S. STEVENS, OF NEW' BRITAIN, CONNECTICUT.

AIR-PUMP.

Application filed. January 17, 1913.

To all whom it may concern Be it known that I, CLAYTON S. STEVENS, a citizen of the United States, residing at New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Air- Pumps, of which the following is a specification.

This invention relates to air-pumps, among the principal objects of the invention being the provision of an article of this character which is simple in construction, compact and powerful in action yet easy of operation.

The pump can be employed with advantage in all the connections that those of the ordinary kind are at present used, although it is of peculiar utility for inflating automobile or like tires. It can, owing to its compactness be stowed away in the toolbox of an automobile or mounted on the running-board thereof.

The device possesses other features of novelty and advantage which with the foregoing will be stated at length in the following description, wherein I will set forth in detail that one of the several forms of embodiment of the invention which I have selected for illustration in the drawings accompanying and forming part of the present specification, this particular disclosure being to enable those skilled in the art to practise the invention. I do not restrict myself to this disclosure; I may depart therefrom in several respects within the scope of the invention defined by my claims.

Referring tosaid drawings: Figure 1 is a top plan view of an air-pump involving my invention. Fig. 2 is a transverse section on the line 22 of Fig. 1, and, Fig. 3 is a longitudinal section on the line 3-3 of said Fig. 1. 9

Like characters refer to like parts throughout the several figures, which are on different scales.

To secure the maximum efficiency I prefer to provide two pistons, a primary or main piston as 2 and a secondary or auxiliary piston as 8. The main piston 151601910- cative in its cylinder 4r, while the auxiliary piston has a like movement in its cylinder 5. As shown the inner removable head 6 of the main cylinder 4 has a tubular extension open at its inner end for a purpose that will hereinafter appear, and this tubular extension is what in the organization illustrated,

Specification Br Letters Patent.

PatentedJan. 25, 1916.

Serial No. 742,527.

presents said secondary or auxiliary cylinder. The head 6 which constitutes a flange at the inner end of said cylinder 5 is detachably connected as by screws 7 to the body of the main cylinder 4. There are various other ways not shown, however, of operatively relating the two cylinders. The main piston 2 is connected with the auxiliary piston 3 by the stem or rod 8, and comprises the body section 9 and the facing section 10. While in the construction shown the stem 8 is integral with the piston member or section 9 and also with the piston 3, this is not essential nor is it necessary that said piston 2 be made in a plurality of parts, although this is an advantageous construction, in that the facing member can act as a. clamp for holding the packing 11 in position. In the construction shown the facing member 10 is held removably in place by a screw 12 tapped into the piston member 9 and also into the stem 8, the head of said screw being countersunk in said facing member.

As w1ll now appear atmospherlc air will pass by the piston 2 on one stroke thereof,

(toward the left as shown) while on the opposite stroke of said piston the air in front of the same will be compressed, and by suitable passage means one form of which will "be hereinafter more particularly described, will be conducted into the auxiliary cylinder in front of the auxiliary piston 8, where it can be further compressed and then supplied to a tire, compressed air containing tank or otherwise. The air is permitted to flow past said piston on what might be considered the air-supply stroke thereof, through a suitable port of which there are preferably, however, several, formed advantageously in the periphery of the piston member 9 and designated by 13. The packing 11 located at the discharge ends of said parts or channels 13, is of disk type and in addition to acting as a packing also performs the oflice of a valve preventing, by its expansion, the escape of air through the channels 18, on the compression stroke of the piston 2. The diameter of the packing 11 is greater than that of the piston member 9 which in turn is of greater diameter than the facing member 10, so that the peripheral or marginal free portion of said packingcan overlie said facing member 10 to an extent sufficient to permit free contraction and expansion of said packing 11 around the margin thereof to permit the free flow of air into the compression space or chamber of the main cylinder 1 from the air-receiving space thereof on the air-receiving movement of the piston, while on opposite movement of said piston, the packing effectually closes on its expansion, the ports 13.

The head 6 is shown having a port 14 opening to atmosphere, so that on the movement of the piston 2 toward the left, atmospheric air, which has entered the receiving space of the cylinder 1 will pass through the channels 13 (the packing l1 contracting during such action) and into the compression side of said cylinder 4:. On the opposite movement of the piston, this air is compressed, the instant that said opposite move ment occurs, the marginal portion of the packing 11 being contracted so as to positively prevent the escape of the air through the ports or passages 13 or through the space between the piston member 9 and the inner wall of the cylinder 4:, said packing on such action closely fitting against such wallaBoth pistons preferably closely fit their cylinders.

There is shown as inserted into the outer side of the piston 3, the shank 15 of the valve carrier or casing 16 fastened as by screws 17 to said piston 3, the packing 18 being clamped between said casing 16 and the piston 3. Except as to size the packing 18 is in construction and function, like the packing 11 already described.

The casing or carrier 16has the chamber 19 in which is located the valve 20 preferably vertically movable' (so as to close by gravity) and faced with leather or some equivalent material to insure a tight fit against its seat situated on the base of said chamber, the stem 21 of said valve being located in the passage 22 preferably of cylindrical form. Said stem 21 has at the termi- -nal thereof opposite that carrying said valve,

the cylindrical guide member 23 sized to freely move in the cylindrical passage 22,

'this cylindrical guide portion 23 insuring straight movement of the valve 20 and the square engagement thereof against its seat. Across the chamber 19 a guard as 21 may extend to prevent accidental dislcdgment of said check valve20.

The stem 8 is longitudinally bored as at V 25 to communicate with the bore 26 through the holding screw 12 and the bore 27 in the shank 15, which last mentioned bore, as will be seen, extends into or intersects the passage 22, so that there will be provided uninterrupted communication between the compression side of the piston 2 and the valve 20. It will be clear,therefore, that on the compression stroke of the piston 2, the air compressed thireby will flow, by way of the passage means already described into and then out of the chamber 19 and in front of the piston 3, the valve 20 being opened by such compressed air. During the compressing movement of the piston 2 the air in front of the piston 3 is not being compressed, such air being compressed on the opposite movement of said piston or that to the left in Fig. 3. The auxiliary cylinder 5 may be equipped with a nipple 28 to which a flexible tube as 29 may be connected to conduct compressed air to a tire, tank or otherwise dispose of the same, a gage 30 of ordinary kind being associated with the tube or pipe 29.

I provide a suitable piston-operating device as the forked rocking lever 31, the lower I ends of the branches of which are pivotally connected as by the pin 32, with lugs 33 depending from said cylinder, the head of said rock lever 31 having a socket to detachably receive thecoperating lever or bar 3 1. This lever 31 when rocked acts through suitable means as the link 35, to reciprocate the two pistons being operatively connected to one of them, for example the piston 2 and extending between its ends, through the port or opening it already described. The outer end of this link 35 is pivoted as at 36 in a notch on the under and inner side of the transverse portion of the rocking lever 31, while the opposite end thereof is pivoted as at 37 to the piston member 9. It willbe noticed that the link 25 is pivoted to the lever approximately centrally thereof, by reason of which the said lever is brought in approximate verti cal alinement with the longitudinal axis of the small cylinder 5 by which compactness is obtained. Owing to the fact that the piston-operating member is located between the ends of the two cylinders, compactness is assuredin a longitudinal direction, lateral compactness being obtained by the fact that the head of the lever 31 is practically in longitudinal alinement with the periphery of the main cylinder.

It will be noted that the cylinders 4 and 5 are connected end to end and as illustiated are coaxial. It will also be evident that the compressed air is conducted from the'compression space of one cylinder to the compression space of the other cylinder by the connecting means, of whatever character the same may be, between the two pistons. By this organization not only compactness but simplicity is assured, in that I eliminate the intermediate chamber sometimes provided I do between coiiperative cylinders and also avoid the necessity of outside connections. not restrict myself as to this particular mat ter, however, as some of the novel features of the invention can be employed in connection with these old types of pumps.

What I claim is:

1. An air pump comprising a primary cylinder, a secondary'cylinder of less diameter than the primary cylinder, the two cylinders being rigidly connected to each other in end to end relation, being coaxial and their adjacent ends being open, primary and secondary pistons reciprocative in the respective cylinders, a stem rigidly connected with the respective pistons and reciprocative through the open end portions thereof, a member provided with a valve chamber, supported on the outer side of the secondary piston, a gravity closable valve in said valve chamber, movable in a direction transverse to the line of movement of the pistons, and passage means connecting the compression space of the primary cylinder with said valve chamber.

2. An air pump comprising primary and secondary connected cylinders disposed end to end, primary and secondary pistons in the respective cylinders, a packing fitted against the secondary piston and engaging the inner Wall of the secondary cylinder, a valve supporting member connected with the secondary piston, for holding said packing in place and having a passage open at its outer end and of two different diameters, a gravity closable valve in the enlarged portion of said passage, provided with a stem mounted in the reduced part of said passage, said stem having a portion slidable in said reduced part, and passage means connecting the compression space of the primary cylinder with said passage.

3. An air-pump comprising primary and secondary connected cylinders disposed end to end, primary and secondary pistons in the respective cylinders, a valve-supporting member comprising a body and a shank, the shank being fitted into said secondary piston and having a longitudinal passage, said body having a radial passage open at its outer end to connect with the compression space of the secondary cylinder, intersected by the other passage and enlarged to present a valve chamber, a gravity-closable valve freely fitted in the enlarged portion of said radial passage, provided with a stem mounted in the reduced part of said radial passage, said stein having a portion slidable in said reduced part, and passage means connecting the compression space of the primary cylinder with said longitudinal passage.

In testimony whereof I afiix my signature in presence of two witnesses.

CLAYTON S. STEVENS.

Witnesses:

F. E. ANDERSON, HEATH SUTHERLAND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

